SEARCH · PubMed Health

Results for “Laser Scanning Cytometry”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

PubMed1995

[Flow cytometry and laser scanning confocal microscopy analysis of the receptor distribution].

To study the physiological regulation of the receptor protein, a fluorescent probe and detection system for alpha 1B-adrenergic receptors have been developed. By using the anti-peptide antibody developed against the alpha 1B-adrenergic receptor NH2-terminus, we have examined the agonist-regulated alpha 1B-adrenergic receptor redistribution in desensitized cells. Flow cytometry analysis showed that anti-peptide antibody against alpha 1B-adrenergic receptor specifically identifies the receptor in CHO cells, COS-7 cells that were transfected with alpha 1B-adrenergic receptor cDNA and rat hepatocytes. Using a fluoro-labeled receptor ligand, BODIPY FL-prazosin, as a probe, cell surface alpha 1-adrenergic receptor subtypes can be detected by flow cytometry. Laser scanning confocal microscopy visualized the agonist-regulated redistribution process of alpha 1B-adrenergic receptor in living cells; thus, following phenylephrine (10(-6) M) stimulation, receptor antigen at the cell surface rapidly internalized and clustered together in a cell within 30 min. The results showed that the antibody and fluoro-labeled ligand are valuable tools for studying the localization and functional role of the alpha 1-adrenergic receptor subtype.

Animals↗

PubMed2003

Oral cytology assessment by flow cytometry of DNA adducts, aneuploidy, proliferation and apoptosis shows differences between smokers and non-smokers.

Oral cytology and morphometric staining is used to identify malignant keratinocytes in oral premalignant or malignant lesions. To detect and to begin to assess changes in oral keratinocytes exposed to tobacco-derived carcinogens, which are at risk for malignant transformation, a novel method is required. The approach uses oral cytology harvested oral keratinocytes analyzed using flow cytometry (FC) for changes in DNA content, damage, cell cycle and apoptosis. Six smoker and six non-smoker oral keratinocytes were evaluated using flow cytometry in the form of laser scanning cytometry (LSC) and laser microdissection (LMD). Among smokers compared to non-smokers, the method detected and assessed DNA damage from tobacco smoke exposure quantifying an enhanced formation of DNA adducts, such as, 8-hydroxy-2'-deoxyguanine (8-OHdG) which creates oxidation lesions and benzo[a]pyrene(B[a]P), which produces a B[a]P)-N2-dG bulky adduct. Increased DNA content, aneuploidy, percentage of cells in synthesis (S) and G(2)+Mitosis (M), and apoptosis were recorded. Tissue and cell controls were used to verify these relationships. Data suggested healthy smokers were at increased risk for malignant transformation of oral keratinocytes because of the changes stated above. Using identical methods, keratinocytes exposed to the tobacco derived carcinogen, B[a]P parallel results obtained from smoke exposure indicating a direct link. Flow cytometric evaluation of oral cytology harvested keratinocytes can be used to measure exposure to tobacco carcinogens, and possibly establish a link to premalignant and malignant transformation before a lesion is noted.

Adult↗

PubMed2001

Effects of paclitaxel on cultured synovial cells from patients with rheumatoid arthritis.

BACKGROUND: Proliferation of synovial cells is considered to play a key role in rheumatoid arthritis (RA). Using paclitaxel, a unique antineoplastic agent known to suppress collagen-induced arthritis, we conducted an in vitro study of cell kinetics on cultured synovial cells from patients with RA. METHODS: Alterations of the cell cycle of cultured fibroblast-like synovial cells (FLSs) from patients with RA were studied using flow cytometry and laser scanning cytometry. Apoptosis and accumulation of cyclin concerning effects of paclitaxel were detected. RESULTS: Paclitaxel induced arrest of the cell cycle at G2/M phase and apoptosis in FLSs. The late stage of apoptosis was determined by the positivity of terminal deoxynucleotidyl transferase assay. Morphological observation by combined usage of both annexin V and propidium iodide on FLSs on a slide glass showed early apoptotic changes in detail. FLSs arrested at G2/M phase showed marked accumulation of cyclin B1. The effects of paclitaxel decreased on FLSs, which diminished proliferative activity. CONCLUSIONS: These data indicate that paclitaxel induces cell arrest at G2/M phase followed by apoptosis in human FLSs, which have high proliferative activity, and possible therapeutic effects of paclitaxel on RA.

Adult↗

PubMed2002

Biotechnology apprenticeship for secondary-level students: teaching advanced cell culture techniques for research.

The purpose of this article is to discuss small-group apprenticeships (SGAs) as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments using both flow cytometry and laser scanning cytometry during the 1-month summer apprenticeship. In addition to effectively and efficiently teaching cell biology laboratory techniques, this course design provided an opportunity for research training, career exploration, and mentoring. Students participated in active research projects, working with a skilled interdisciplinary team of researchers in a large research institution with access to state-of-the-art instrumentation. The instructors, composed of graduate students, laboratory managers, and principal investigators, worked well together to present a real and worthwhile research experience. The students enjoyed learning cell culture techniques while contributing to active research projects. The institution's researchers were equally enthusiastic to instruct and serve as mentors. In this article, we clarify and illuminate the value of small-group laboratory apprenticeships to the institution and the students by presenting the results and experiences of seven middle and high school participants and their instructors.

Animals↗

PubMed2002

Translocation of an intracellular antigen to the surface of medullary breast cancer cells early in apoptosis allows for an antigen-driven antibody response elicited by tumor-infiltrating B cells.

Tumor-infiltrating lymphoplasmacytic cells are a key feature of medullary carcinoma of the breast (MCB), a distinct subtype of human breast cancer that, despite cytologically anaplastic characteristics, has a more favorable prognosis than other types of breast cancer. Since it has been proposed that the improved clinical outcome is due at least in part to the presence of a prominent lymphoplasmacytic cell infiltrate in the tumor stroma, we recently examined the tumor-infiltrating B cell response in MCB and showed that it is oligoclonal and directed against an intracellular protein translocated to the cell surface upon MCB cell apoptosis. Human Abs cloned from MCB lymphoplasmacytic infiltrate-derived phage display libraries and reflecting the dominant part of the response were used to identify the target Ag as actin. Here, we have characterized in detail the cloned human IgG Abs and the translocation process of actin to the cell surface of apoptotic MCB cells. Our analysis shows that the cloned Abs bind specifically and with high affinity to actin, as determined by ELISA and surface plasmon resonance. Sequence analysis revealed that the Abs are highly somatically mutated, with high replacement to silent ratios, indicative of an Ag-driven, affinity-matured response. Interestingly, the tumor-infiltrating B cells in half the MCB patients mainly exhibited an IgG2 response, while IgG1 dominated in the others. To gain insight to the molecular events that may elicit such an Ab response, we examined the translocation of actin to the cell surface of apoptotic MCB cells using flow cytometry and laser scanning cytometry. Our results show that actin becomes exposed on the cell surface of a large proportion of apoptotic MCB cells as an early apoptotic event. We propose that the Ab response against actin produced by tumor-infiltrating B lymphoplasmacytic cells is Ag-driven, affinity-matured, and elicited due to the increased rate of apoptosis occurring within the MCB tumor that facilitates the translocation and proteolytic fragmentation of intracellular proteins.

Actins↗

PubMed2006

Assessment of reprocessed arthroscopic shaver blades.

PURPOSE: The purpose of this study was to evaluate the level of contaminants on, as well as the quality of, reprocessed shaver blades. METHODS: We assessed 7 new shaver blades and 27 shaver blades that had been reprocessed with mechanical cleaning, functional testing, and sterilization with ethylene oxide. A spectrophotometer measured the amount of nucleic acid and protein. The blade quality was assessed by photographing the blades with magnification and determining the percentage of damage present on each blade. A subset of shaver blades were then used to cut meniscal tissue, and the cut surface was measured for smoothness by image processing and automated laser scanning cytometry. In evaluation of the meniscus, for the subset of shavers, an image processing value of 1 indicates a smooth, straight line, and values lower than 1 reflect deviations in the cut surface (the closer the value is to 1, the smoother the surface). Laser scanning cytometry values indicate the percentage of irregularities in the cut surface (the lower the value is, the smoother the surface). RESULTS: Of the 27 reprocessed shaver blades, 13 (48%) had detectable levels of protein and 17 (63%) had detectable levels of nucleic acid. On the reprocessed shaver blades, protein levels ranged from 2.43 microg to 60 microg and nucleic acid levels ranged from 0.40 microg to 3.5 microg. No new shaver blade had contaminants. Twenty reprocessed shaver blades had been manufactured with teeth and could be evaluated for visible damage. Of these, 10 had 1% to 25% damage, 5 had 26% to 50% damage, 3 had 51% to 75% damage, and 2 had 76% to 100% damage. The new blades had no visible damage. Image processing revealed smoothness of the surface cut with new shaver blades, yielding values of 1 +/- 0.12, whereas the values for reprocessed shaver blades ranged from 0.62 +/- 0.02 to 1 +/- 0.07. Laser scanning cytometry values ranged from 3.3% to 7.1% for the new blades as compared with 5.8% to 20.0% for the reprocessed blades. CONCLUSIONS: Of the reprocessed shaver blades, 48% had detectable levels of protein and 63% had detectable levels of nucleic acid. All of the reprocessed blades visually evaluated showed some level of damage or wear, whereas no new blade had such damage. In addition, menisci cut with reprocessed shavers showed rougher edges than did menisci cut with new shavers. CLINICAL RELEVANCE: To make an informed decision regarding the use of reprocessed shaver blades, surgeons will want to know the level of contamination on, and the quality of, reprocessed shaver blades.

Animals↗

PubMed2006

Fluorescent protein-based cellular assays analyzed by laser-scanning microplate cytometry in 1536-well plate format.

Microtiter plate readers have evolved from photomultiplier and charged-coupled device-based readers, where a population-averaged signal is detected from each well, to microscope-based imaging systems, where cellular characteristics from individual cells are measured. For these systems, speed and ease of data analysis are inversely proportional to the amount of data collected from each well. Microplate laser cytometry is a technology compatible with a 1536-well plate format and capable of population distribution analysis. Microplate cytometers such as the Acumen Explorer can monitor up to four fluorescent signals from single objects in microtiter plates with densities as high as 1536 wells. These instruments can measure changes in fluorescent protein expression, cell shape, or simple cellular redistribution events such as cytoplasmic to nuclear translocation. To develop high-throughput screening applications using laser-scanning microplate cytometry, we used green fluorescent protein- and yellow fluorescent protein-expressing cell lines designed to measure diverse biological functions such as nuclear translocation, epigenetic signaling, and G protein-coupled receptor activation. This chapter illustrates the application of microplate laser cytometry to these assays in a manner that is suitable for screening large compound collections in high throughput.

Active Transport, Cell Nucleus↗

PubMed2005

Comparative analysis of the effects of sample source and test methodology on the assessment of protein expression in acute myelogenous leukemia.

Numerous studies have analyzed the expression and prognostic importance of various proteins in acute myelogenous leukemia (AML). We sought to determine whether the sample source and methodology used to measure protein expression affect the results obtained. To determine the importance of sample source, we used Western blotting to compare the expression of eight proteins and phosphoproteins in the leukemia blast-enriched fraction of 118 blood- and 108 marrow-derived samples, including 37 paired samples. To determine the importance of methodology, the expression of five proteins was measured in 20 paired samples by Western blotting, laser scanning cytometry (LSC), and flow cytometry. The mean expression and range of expression in blood- and marrow-derived samples were statistically identical for all eight proteins. Expression measurements for the 37 paired blood and marrow samples also had very high statistical correlation. The LSC and flow cytometry data had the highest concordance when compared using Kolmogorov-Smirnoff D-stats (range of R values, 0.8-1.0). High concordance was also observed between the LSC and flow cytometry results when the percentage of cells positive for expression was dichotomized into positive or negative expression. However, there was less correlation between LSC and flow cytometry when the actual percentages of positive cells were compared. The majority of discordant situations involved samples that were positive by flow cytometry but negative by LSC. The correlation between Western blotting signal intensity and the percentage of expression-positive cells measured by LSC or flow cytometry varied by protein but was limited when there was little heterogeneity in expression by either method. In conclusion, provided that leukemia blast-enriched fractions were analyzed, the blood- and marrow-derived samples had identical protein expression. There was good concordance of results between flow cytometry and LSC, which share similar technology, but more limited correlation between these methods and Western blotting.

Blotting, Western↗

PubMed1999

Sensitive detection of Escherichia coli O157:H7 in food and water by immunomagnetic separation and solid-phase laser cytometry.

Rapid, direct methods are needed to assess active bacterial populations in water and foods. Our objective was to determine the efficiency of bacterial detection by immunomagnetic separation (IMS) and the compatibility of IMS with cyanoditolyl tetrazolium chloride (CTC) incubation to determine respiratory activity, using the pathogen Escherichia coli O157:H7. Counterstaining with a specific fluorescein-conjugated anti-O157 antibody (FAb) following CTC incubation was used to allow confirmation and visualization of bacteria by epifluorescence microscopy. Broth-grown E. coli O157:H7 was used to inoculate fresh ground beef (<17% fat), sterile 0.1% peptone, or water. Inoculated meat was diluted and homogenized in a stomacher and then incubated with paramagnetic beads coated with anti-O157 specific antibody. After IMS, cells with magnetic beads attached were stained with CTC and then an anti-O157 antibody-fluorescein isothiocyanate conjugate and filtered for microscopic enumeration or solid-phase laser cytometry. Enumeration by laser scanning permitted detection of ca. 10 CFU/g of ground beef or <10 CFU/ml of liquid sample. With inoculated meat, the regression results for log-transformed respiring FAb-positive counts of cells recovered on beads versus sorbitol-negative plate counts in the inoculum were as follows: intercept = 1.06, slope = 0.89, and r2 = 0. 95 (n = 13). The corresponding results for inoculated peptone were as follows: intercept = 0.67, slope = 0.88, and r2 = 0.98 (n = 24). Recovery of target bacteria on beads by the IMS-CTC-FAb method, compared with recovery by sorbitol MacConkey agar plating, yielded greater numbers (beef, 6.0 times; peptone, 3.0 times; water, 2.4 times). Thus, within 5 to 7 h, the IMS-CTC-FAb method detected greater numbers of E. coli O157 cells than were detected by plating. The results show that the IMS-CTC-FAb technique with enumeration by either fluorescence microscopy or solid-phase laser scanning cytometry gave results that compared favorably with plating following IMS.

Animals↗

PubMed1996

Intracellular localization of cyclin B1 during the cell cycle in glioma cells.

We investigated cyclin B1 expression during the cell cycle in human glioma cells cultured under asynchronous growing condition by two cytometry techniques: flow cytometry (FCM) and laser scanning cytometry (LSC). FCM analysis revealed the specific accumulation of cyclin B1 in G2/M phase with a wide intercellular variation (Dunphy WG: Trend Cell Biol 4:202-207, 1994). It is noteworthy that LSC, which is characterized by rapid quantitative analysis followed by imaging, allows morphological observation of the intracellular distribution of cyclin B1 as a function of cell cycle position cell by cell (Hunter T: Cell 75:839-841, 1993). Cyclin B1 was virtually undetectable in cells from G0/G1 phase to mid S phase, but became visible in the cytoplasm in late S phase. As cells proceeded within G2 phase, the level of cyclin B1 rapidly increased in the perinuclear region of the cytoplasm, but cyclin B1 was still faintly present in the nucleus. Cyclin B1 appeared in the nucleus at the mitotic phase. Then the nuclear membrane was disrupted and cyclin B1 was distributed evenly in the cell. The level of cyclin B1 was maximum in metaphase. However, it abruptly degraded at the end of metaphase, and subsequently G1 cells were cyclin B1 negative.

Cell Cycle↗

PubMed1999

High-resolution cytometry of FISH dots in interphase cell nuclei.

BACKGROUND: Flow cytometry (FCM) and laser scanning cytometry (LSCM) provide indispensable tools for measuring large number of cells with low resolution. Confocal microscopy, on the other hand, is used for measuring small number of cells with high resolution. In this paper, we present a reasonable compromise between the two extremes. METHODS: We have developed a completely automated, high-resolution system (high-resolution cytometer, HRCM) capable of analyzing microscope slides with FISH-stained interphase nuclei in two dimensions as well as in three dimensions using a fully motorized epi-fluorescence microscope and a cooled digital CCD camera fully controlled by a high-performance computer which performs both acquisition and related on-line image analysis. The images of different dyes are acquired sequentially using highly specific filters and superimposed in computer memory. For each nucleus and each hybridization dot, user-selected attributes (such as position, size, intensity, etc.) are computed off-line using another processor or computer connected with a network. RESULTS: Using HRCM, it is possible to analyze multi-color preparations including UV-excited dyes as well as repeatedly hybridized preparations reacquiring individual nuclei. The speed of the acquisition and analysis is about 50 nuclei per minute in two dimensions and 1 nucleus per minute in three dimensions, but depends on the density of nuclei on the slide; the precision of the lateral and axial measurements is approximately 100 nm. CONCLUSIONS: Thus, using overnight acquisition, quantities comparable to those of FCM or LSCM measurements can be analyzed with an accuracy comparable to confocal microscopy. HRCM is suitable for a number of clinical and scientific tasks: routine diagnostics, follow-up of therapy, studies of chromatin structure, and many other different aspects of cell research.

Cell Nucleus↗

PubMed1999

Cytometric analyses to distinguish death processes.

The morphological changes typical of apoptosis, as well as the loss of integrity of the plasma membrane and the breakdown of nuclear DNA provide numerous features that permit recognition of apoptotic cell death by various methods. Flow cytometry (FCM) and laser scanning cytometry (LSC) allow for accurate and rapid measurement of apoptosis in both cultures and clinical samples (e.g. solid tumors, bone marrow aspirates, peripheral blood etc.). Furthermore, both FCM and LSC enable one to correlate the apoptosis with the position of the dying cell in the cell cycle. Discussion includes the cytometric identification and quantitation of apoptotic or necrotic cells, based on the analysis of a particular biochemical or molecular feature that is characteristic for either necrosis or apoptosis.

Animals↗

PubMed2001

Laser-based microscopic approaches: application to cell signaling in environmental lung disease.

Cell-imaging approaches using new laser-based technologies have a wide applicability to thefields of pathology and cell biology. Here, we present the application of several of these techniques, including confocal scanning laser microscopy (CSLM), laser scanning cytometry (LSC), and laser capture microdissection (LCM), to studies of cell signaling by environmental agents in lung disease. Using both cells in culture and lung tissue, we show that these technologies are powerful tools for understanding signal transduction cascades elicited by toxic agents, such as oxidants and asbestosfibers, and their relationship to the development of cell injury and proliferation, responses leading to lung disease and/or repair.

Air Pollutants↗

PubMed2005

Green tea polyphenol epigallocatechin gallate inhibits adipogenesis and induces apoptosis in 3T3-L1 adipocytes.

OBJECTIVE: Green tea catechins have been shown to promote loss of body fat and to inhibit growth of many cancer cell types by inducing apoptosis. The objective of this study was to determine whether epigallocatechin gallate (EGCG), the primary green tea catechin, could act directly on adipocytes to inhibit adipogenesis and induce apoptosis. RESEARCH METHODS AND PROCEDURES: Mouse 3T3-L1 preadipocytes and mature adipocytes were used. To test the effect of EGCG on viability, cells were incubated for 3, 6, 12, or 24 hours with 0, 50, 100, or 200 microM EGCG. Viability was quantitated by MTS assay. To determine the effect of EGCG on apoptosis, adipocytes were incubated for 24 hours with 0 to 200 microM EGCG, then stained with annexin V and propidium iodide and analyzed by laser scanning cytometry. Both preadipocytes and adipocytes were also analyzed for apoptosis by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. To determine the effect of EGCG on adipogenesis, maturing preadipocytes were incubated during the 6-day induction period with 0 to 200 microM EGCG, then stained with Oil-Red-O and analyzed for lipid content. RESULTS: EGCG had no effect on either viability or apoptosis of preconfluent preadipocytes. EGCG also did not affect viability of mature adipocytes; however, EGCG increased apoptosis in mature adipocytes, as demonstrated by both laser scanning cytometry and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays. Furthermore, EGCG dose-dependently inhibited lipid accumulation in maturing preadipocytes. DISCUSSION: These results demonstrate that EGCG can act directly to inhibit differentiation of preadipocytes and to induce apoptosis of mature adipocytes and, thus, could be an important adjunct in the treatment of obesity.

3T3-L1 Cells↗

PubMed2003

Determination of features indicating progression in atypical squamous cells with undetermined significance: human papillomavirus typing and DNA ploidy analysis from liquid-based cytologic samples.

BACKGROUND: The Bethesda System of cervical cytologic findings introduced the term ASCUS (atypical squamous cells of undetermined significance) to cover the broad zone separating normal cytomorphology from definitive squamous intraepithelial lesions (SILs). The management of patients with ASCUS is particularly problematic as approximately 10% of ASCUS patients develop SIL and 1 per 1000 develop cervical carcinoma. METHODS: Our aim was to demonstrate the combined use of polymerase chain reaction for human papillomavirus (HPV) typing and laser scanning cytometry for DNA content measurements in the subcategorization of ASCUS cases according to the risk for progression toward cancer. Liquid- based monolayer preparation (ThinPrep, Cytyc, Boston, MA) of the cytologic material was used for cytomorphologic analysis. DNA content measurements using laser scanning cytometry and direct sequencing of HPV using the consensus primers GP5+/GP6+ and MY09/MY11 were performed from the same material. RESULTS: Twelve of the 44 cases (27.2%) with ASCUS carried a high-risk HPV genome whereas only 3 of the 195 normal control cases (1.5%) showed positivity for a high-risk HPV genome. Six of 12 (50%) of the high-risk HPV-positive ASCUS cases presented isolated cells with a DNA content above 5c, whereas cells with a DNA content above 9c were found in 3 of 12 cases (25%) and were exclusively found in combination with high-risk HPV infection. In these three cases, the histologic follow-up resulted in cervical intraepithelial neoplasia (CIN) I (one case) and CIN III (two cases). None of the other ASCUS or normal cases displayed DNA aneuploidy above 9c. They returned to normal cytology (within normal limits/benign cellular changes) in the follow-up. CONCLUSIONS: Human papillomavirus typing and DNA content measurements may delineate a distinct group of ASCUS. Our preliminary data suggest that ASCUS cases with high-risk HPV positivity and with rare cells with abnormally high DNA content represent similar biologic features as high-grade SIL and are at elevated risk to develop cancer.

Carcinoma, Squamous Cell↗

PubMed2001

Neuroblastic and Schwannian stromal cells of neuroblastoma are derived from a tumoral progenitor cell.

The coexistence of neuroblastic and Schwannian stromal (SS) cells in differentiating neuroblastoma (NB), and derivation of Schwannian-like cells from neuroblastic clones in vitro, were accepted previously as evidence of a common pluripotent tumor stem line. This paradigm was challenged when SS cells were suggested to be reactive in nature. The advent of microdissection techniques, PCR-based allelic analysis, and in situ fluorescent cytometry made possible the analysis of pure cell populations in fresh surgical specimens, allowing unequivocal determination of clonal origins of various cell subtypes. To overcome the complexity and heterogeneity of three-dimensional tissue structure, we used: (a) Laser-Capture Microdissection to obtain histologically homogeneous cell subtype populations for allelotype analysis at chromosomes 1p36, 11q23, 14q32, and 17q and study of MYCN copy number; (b) multiparametric analysis by Laser-Scanning Cytometry of morphology, DNA content, and immunophenotype of intact cells from touch imprints; and (c) bicolor fluorescence in situ hybridization on touch imprints from manually microdissected neuroblast and stroma-rich areas. Histologically distinct SS and neuroblastic cells isolated by Laser-Capture Microdissection had the same genetic composition in 27 of 28 NB analyzed by allelic imbalance and gene copy number. In all 20 cases studied by Laser-Scanning Cytometry, SS cells identified by morphology and S-100 immunostaining had identical DNA content and GD2-staining pattern as their neuroblastic counterparts. In 7 cases, fluorescence in situ hybridization demonstrated the same chromosomal makeup for SS and neuroblastic cells. These results provide unequivocal evidence that neuroblastic and SS cells in NB are derived from genetically identical neoplastic cells and support the classical paradigm that NB arises from tumoral cells capable of development along multiple lineages.

Adolescent↗

PubMed2005

Shaver, bipolar radiofrequency, and saline jet instruments for cutting meniscal tissue: a comparative experimental study on sheep menisci.

PURPOSE: The purpose of this study was to compare the quality of meniscal tissue cut with 3 different surgical instruments (traditional shavers, bipolar radiofrequency (RF) wands, and a high-pressure saline jet) and that of control menisci. TYPE OF STUDY: Experimental design, biochemical and histologic study. METHODS: Sixty samples of sheep menisci were separated into 4 groups. Three groups were shaved on the apical surface with the different instruments. The smoothness of the cut surfaces was evaluated visually by an orthopaedic surgeon and then scored by laser scanning cytometry and by line measurement analysis. The depth of tissue damage was measured by fluorescent cytochemistry. Means and standard deviations were calculated and comparative statistics used (P < .05). RESULTS: The edges cut by the saline jet and bipolar RF were significantly smoother when judged by the surgeon than those cut by traditional shaver. There was no significant difference between the saline jet and bipolar RF. There were no significant differences in smoothness when measured by laser scanning cytometry or by line measurement techniques. The control menisci had less depth of damage along the edge as measured by fluorescent cytochemistry than did any of the menisci cut with the instrument. The saline jet had significantly less depth of damage than did the shaver. No other significant differences existed between the instruments for depth of damage. CONCLUSIONS: The results of our investigation conclude that high-pressure saline instruments may cause less damage to residual meniscal tissue when compared with bipolar RF and shavers. Saline jets and bipolar RF also produce a smoother cut than shavers. CLINICAL RELEVANCE: Surgeons may want to consider the degree of residual damage to meniscal tissue from the application of various surgical instruments. Saline jets may be a superior cutting instrument than RF or shavers when considering depth of residual damage and smoothness of residual meniscal edges.

Animals↗

PubMed1997

Methods for automatic multiparameter analysis of fluorescence in situ hybridized specimens with a laser scanning cytometer.

Multiparameter laser scanning cytometry has been applied to the automatic counting of probe spots and the simultaneous measurement of cellular DNA for fluorescence in situ hybridization (FISH) prepared specimens counterstained with propidium iodide. Relatively low resolution imaging, highly variable probe fluorescence, spectral overlap of probe with counterstain fluorescence, and autofluorescence required the development of an image processing method to detect and isolate FISH probe spots. Inability to properly apportion detected probe spots because of overlapping probe spot images in the same cell required development of a method to eliminate cell data whenever spots in that cell could not be reliably isolated. Laser scanning cytometry incorporating these methods to determine per cell probe spot count and DNA is demonstrated on tissue cultures and peripheral blood cells using different centromeric FISH probes with either FITC or Spectrum Green labeling.

Cells, Cultured↗